I guess the tool you posted is lesser quality. I got this one. http://www.micromark.com/triton-resistance-soldering-iron,7890.html
I use the 50 amp for soldering fine details, like mirrors wire handrails, & jewelry. 100 amps is more than enough, I have soldered 1/8 thick Brass many times, I have used it on 1/16th scale Farm toys, and 1/64th farm toys 7 trucks & other items needing soldering. I do NOT have any Brass rolling stock, so have never tried for that. Martin
